Wireless personal area networks (WPANs) are used to convey information over relatively short distances. A WPAN may transfer data at a relatively low rate to minimize power consumption. Unlike wireless local area networks (WLANs), WPANs employ little or no infrastructure. Consequently, WPANS allow small, power-efficient, and inexpensive solutions to be implemented for a wide range of devices.
Smart Utility Networks (SUNs) are one application of WPAN technology. A SUN may operate either over short ranges such as in a mesh network where utility meter information is sent from one utility meter to another, or over longer ranges such as in a star topology where utility meter information is sent to a pole-top collection point. The terms WPAN and SUN are used interchangeably herein.
In wireless communications systems, transmissions between devices encounter a variety of stationary and moving reflective surfaces (buildings, vehicles, etc.). In WPANs using orthogonal frequency division multiplexing (OFDM), relative motion of a transmitter, receiver, or reflective surface can cause Doppler shift in the carrier frequencies that produces inter-carrier interference.